Boreskov

GROWTH OF MICROORGANISMS IN MARTIAN‐LIKE SHALLOW SUBSURFACECONDITIONS: LABORATORY MODELLINGPavlov A.K.*, Shelegedin V.N.**, Vdovina M.A. and Pavlov A.A.****Ioffe Physical Technical Institute of Russian Academy of Sciences, Saint‐Petersburg, Russia**Saint Petersburg Polytechnical University, St. Petersburg, Russia***NASA Goddard Space Flight Center, Crofton, USALow atmospheric pressures on Mars and the lack of substantial amounts of liquid waterwere suggested to be among the major limiting factors for the potential Martian biosphere.However, large amounts of ice were detected in the relatively shallow subsurface layers ofMars by the Odyssey Mission and when ice sublimates the water vapour can diffuse throughthe porous surface layer of the soil. Here we studied the possibility for the active growth ofmicroorganisms in such a vapour diffusion layer.Our results showed the possibility of metabolism and the reproduction of nonextremophileterrestrial microorganisms (Vibrio sp.) under very low (0.01–0.1 mbar)atmospheric pressures in a Martian‐like shallow subsurface regolith.121